Apparatus for use in the determination of grain sizes in granular material



Aug. 7, 1934. M, VOGEL-JORGENSEN 1, A

APPARATUS FOR USE IN THE DETERMINATION OF GRAIN SIZES IN GRANULAR MATERIAL Filed Dec. 3, 1931 INVENTOR. Mag I Patented Aug. 7, 1934 UNITED STATES 7 1,969,081 APPARATUS FOR USE IN THE DETERMINA- TION MATERIAL OF GRAIN SIZES IN GRANULAR Mikael Vogel-Jorgensen, Copenhagen, Denmark, assignor to F. L. Smidth & (30., New York, N. Y., a corporation of New Jersey Application December 3, 1931, Serial No. 578,708 In France December 26, 1930 2 Claims.

In various industries, in which is involved the treatment of more or less finely granulated material, as in the manufacture of hydraulic cement it is necessary to determine from time to time the grain sizes of the material. In laboratory practice a homogeneous mixture of the material to be analyzed is made in a suitable liquid.-

If the mixture is left at rest the grains will precipitate, the larger grains precipitating further and more rapidly than the smaller grains. As it is possible to calculate the rate at which a grain of given size will precipitate in a given liquid it is possible to calculate the time it will take for grains of different sizes to precipitate from the surface of the liquid to a determined depth and conversely, when the depth is known at which grains are found after a lapse of a known period of time, it is possible to calculate the size of the grain. If at the same time the concentration of the material at a certain given depth is known it is possible to determine the relation between the amount of material and the size of the grains. In laboratory practice these determinations are made by taking out, by means of a pipette, samples of the mixture at the same depth but after different lapses or" time. It is the object of the present invention to provide an apparatus by which such determinations can be facilitated and results secured without undue delay. The invention will be more fully explained in reference to the accompanying drawing in which it is illustrated, and in which:

Figure l is a view in sectional elevation of an apparatus constructed in accordance with the invention.

Figure 2 is a detail view in section on a somewhat larger scale of a portion of the apparatus.

In the drawing there is indicated at a a suitable container, preferably of glass, which may have etched or otherwise formed on its surface a vertical scale I). The neck of the container is shown as fitted with a stopper 0 through which may be introduced into the container a plurality of pipettes d, e and the pipettes being extended to difierent lengths within the container so that their open lower ends shall stand at different depths below the surface of the fluid mixture which is to be introduced into the container. The stopper 0 should be provided with a vent g to permit equalization of pressure within the container with the atmosphere. At a suitable distance above the stopper each pipette may be provided with a valve cock, as at h, and the several pipettes may be joined and connected through a valve cock i, preferably a two-way cock, with a container k. By the use of this apparatus it is possible to take out samples of a mixture from the container 0!. at different depths, each sample being discharged, when the liquid has been sucked up in the pipettes and into the container is (and the respective valve cock h. is opened), from which the sample may be withdrawn through the two-way cock 1' and discharged into a suitable receptacle. As the several samples are taken successively from the mixture, at different depths, and after the lapse of a predetermined period of time, the sizes of the grains taken at different depths can be determined without loss of time. It will be noted that the time required for analysis of a mate-. rial is fixed by the time required for the smallest grain to sink to the level at which the sample is taken. Under the old practice, in which the sample was taken at the bottom of the container, this elapsed time was very long, whereas with the improved apparatus several samples are taken at different depths and the determination is made from the several samples. The time allowed for precipitation may be as short as compatible with exactness of determination. It will be understood that adjustment of the pipettes may be made for different conditions.

I claim as my invention:

1. An apparatus for use in the determination of grain sizes of granular material comprising a container for a liquid mixture of the material to be analyzed, a plurality of pipettes of different lengths, means to support the pipettes with their open lower ends at difierent. depths in the container, each pipette being provided with a valve cock above the supporting means, a sec ond container into which the sample taken by each pipette may be discharged when the valve cock is opened, and a means including a valve cock for establishing connection between the last named container and the several pipettes.

2. An apparatus for use in the determination of grain sizes of granular material comprising a container for a liquid mixture of the material to be analyzed, a plurality of pipettes of different lengths, means to support the pipettes with their open lower ends at different depths in the container, each pipette being provided with a valve cock above the supporting means, a second container into which the sample taken by each pipette may be discharged when the valve cock is opened, and a means for establishing connection between the last named container and the several pipettes, the last named means being provided with a two-way cock.

MIKAEL VOGEL-JORGENSEN. 

